Yes, 128 GB is a bit small for a hard drive these days. But SSD technology has improved performance, longevity and capacity. Up to 100 TB storage is now available, but generally a 500 GB is more than enough for most needs. Just ensure that the BIOS configuration can accept the drive's statistics. Or you may need to create a primary partition in keeping within the BIOS limitations. Windows will have no problems (or should not) with different hard drive/partition size, but likely not accept different system features.
As to upgrading the CPU in any motherboard, check with the provider's site as to compatibility from the QVL (qualified vendor list) for what can be used. Maybe a BIOS update will allow the newer CPU or memory type, but not always. Chipset design is a major issue too. A chipset cannot be changed or upgraded.
As to dropouts with any storage drive, a program such as Seagate Sea Tools® from
https://www.seagate.com/support/downloads/seatools/ can work on almost any hard drive type, and if minor problems can be masked, more life can be had from the drive. But any defects in the boot sector or FAT (file access tables) can spell doom for a hard drive.
SSD drives have no moving parts, but the memory lattice does have a limited life for energizing and blanking storage clusters.